This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Valium and related drugs, referred to as "benzodiazepines" are prescribed widely for the treatment of anxiety and sleep disorders, two of the most common psychiatric disorders in the U.S. Benzodiazepines are considered to be among the safest prescription drugs in modern medicine, but they unfortunately are also drugs of abuse, with higher prevalence in women than men. The aim of this revision to our parent grant is to uncover sex differences in the abuse potential of benzodiazepines, with the overall goal of developing safer drugs for treating anxiety and sleep disorders regardless of gender.